Specifically, though not exclusively, the invention can be used for controlling the periodic opening of the valves in a compressed-air device for cleaning a dust filter, in which the valves are closed during normal use of the filter and are periodically opened so as to send compressed air on to the filtering surfaces of the filter itself.
In particular reference is made to a pulse generator able to receive a pneumatic signal in input and to transform this signal into an output signal constituted by a succession of pulses which can be used to pilot an apparatus. The output signal is obtained by exploiting the time necessary for a chamber supplied with a pressurised gas to reach a predetermined pressure.
Pneumatic pulse generators are known in the prior art and send in output a succession of square waves, and which are suitable for receiving compressed air at relatively high pressure (above 2 bar) in input.
Other known pulse generators use a relatively low-pressure compressed air source (lower than 2 bar) and require the use of wave amplifiers.
This last type of pulse generator is unsuitable for use in the field of industrial applications such as, for example, controlling valve opening in dust filter cleaning devices.
The main aim of the present invention is to provide a pneumatic pulse generator which can use compressed air at relatively low pressures (for example, comprised between 0.5 and 2 bar) without any need for a wave amplifier.
An advantage of the invention is that it makes available a pulse generator which can simply and immediately regulate both work time (that is, the duration of a pulse) and pause time (that is, the time comprised between two consecutive pulses).
A further advantage of the invention is that the pulse generator is extremely reliable and resilient.
A still further advantage is that the pulse generator can function effectively without return springs or other like elements which are susceptible to rapid wear and thus have to be frequently substituted.